II. Precautions
- Children with Headaches lacking neurologic findings do not require neuroimaging
- Incidence of significant neuroimaging findings is <1%
- Hayes (2018) J Am Coll Radiol 15(5): S78-90 [PubMed]
III. Indications: Head Imaging (typically MRI Brain with and without contrast)
- See Headache Red Flags
- Trigeminal autonomic Cephalgia (Cluster Headache, Paroxysmal Hemicrania, Hemicrania Continua, SUNCT Syndrome)
- Headache with new features or focal neurologic deficits
- Altered Level of Consciousness
- Increased Intracranial Pressure suspected
- Seizures
- Suspected intracranial infection
- Suspected intracranial abnormality
-
Chronic Progressive Headache over weeks to months
- Neuroimaging recommended for organic Headache Evaluation, but yield is 1%
IV. Imaging
-
CT Head
- First-line study in acute neurologic findings (Hemorrhage, Head Trauma, CVA)
- Identifies Intracranial Hemorrhage, Skull Fracture, CNS mass or abscess
-
MRI Head without Contrast
- Identifies structural abnormalities (e.g. Hydrocephalus, mass effect)
- Consider in Seizures
-
MRI Head with Gadolinium contrast
- Avoid Gadolinium contrast in severe Chronic Kidney Disease and pregnancy
- Contrast enhancement occurs in regions of inflammation or infection
- Consider in CNS malignancy, infection, inflammation, Multiple Sclerosis
V. Protocol: Imaging Selection
-
Immunocompromised
- MRI Head with and without contrast
-
Temporal Arteritis suspected in age >60 years
- MRI Head with and without contrast
- Requires starting Corticosteroids and obtaining temporal artery biopsy (or other specific diagnostics)
- Suspected Meningitis
- CT Head or MRI Head without contrast
- Start Antibiotics and obtain Lumbar Puncture
- Pregnancy and severe Headache
- Suspected carotid dissection with severe unilateral Headache
- Sudden onset severe Headache (first or worst, thunderclap)
- CT Head without contrast followed by Lumbar Puncture (reflex if positive to CTA Head and neck) or
- MRI Head with and without contrast and MRA Head and neck
-
Thrombophilia or other Cerebral Venous Thrombosis risk factors
- MRI with Magnetic Resonance Venogram (MRI/MRV) or CT with CT Venogram (CT/CTV)
- First Seizure Evaluation
VI. References
- Broder (2023) Crit Dec Emerg Med 37(3): 16-7
- Strain (2000) Radiology 215(suppl):855-60 [PubMed]
- Douglas (2014) J Am Coll Radiol 11(7): 657-67 [PubMed]